The technology relates to a control apparatus of an electric vehicle.
There are electric vehicles with a traction motor and an engine, such as hybrid electric vehicles (HEVs) or plug-in hybrid electric vehicles (PHEVs). A typical electric vehicle includes a main battery and a sub-battery. The main battery supplies electric power to the traction motor, whereas the sub-battery supplies electric power to other electrical parts.
A certain type of electric vehicle controls its operation mode by switching between an engine operation mode and an engine non-operation mode, depending on a state of the main battery. In the engine operation mode, the electric vehicle runs with the engine operating. In the engine non-operation mode, the engine stops, and the electric vehicle runs on the power of the traction motor. Performing the control in this manner enables the electric vehicle to, even when a remaining amount of electric power charged in the main battery is lowered during the running in the engine non-operation mode, continue to run by operating the engine while charging the main battery with the engine power. Furthermore, when any abnormality occurs in the main battery during the running in the engine non-operation mode, the electric vehicle is able to continue to run by starting up the engine.
Japanese Unexamined Patent Application Publication (JP-A) No. 2014-218130 discloses a technique in which a traveling mode of an electric vehicle is switched on the basis of: chargeable power Win that indicates a limit of chargeable electric power of a main battery; dischargeable power Wout that indicates a limit of dischargeable power of the main battery; a state of charge (SOC); and a battery temperature. Reference is made to FIG. 13 of JP-A No. 2014-218130.
Japanese Unexamined Patent Application Publication (JP-A) No. 2015-131565 discloses a technique in which a sub-battery is charged with electric power of an electric generator when an engine operates, whereas the sub-battery is charged with electric power of a main battery when the engine stops.